When an oil/fat-containing processed food is produced, there is a demand for using particularly a powdered oil/fat in consideration of easy handling, workability, and easy application to foods of various forms. A number of powdering techniques of an oil/fat containing mainly triglycerides have conventionally been disclosed (for example, Japanese Patent Laid-Open No. 50-110403, Japanese Patent Laid-Open No. 56-104998, Japanese Patent Laid-Open No. 57-159896, and Japanese Patent Laid-Open No. 8-56604).
Techniques of making use of partial glycerides for an oil/fat powder are also disclosed. For example, disclosed in Japanese Patent Laid-Open No. 62-210975 is a technique of covering an oil/fat powder with medium-chain fatty acid mono-diglycerides, thereby improving its dispersibility in cold water. This technique is however accompanied with the drawbacks that addition of the covering step makes the preparation process cumbersome, dispersibility in powder such as protein and carbohydrate is inferior owing to the low content of medium-chain fatty acid mono-diglycerides and the medium-chain fatty acids introduce an undesirable taste peculiar thereto.
In Japanese Patent Laid-Open No. 6-172782, proposed is a technique relating to a highly-unsaturated-fatty-acid-containing monoglyceride powder. This technique makes it possible to impart the powder with excellent water dispersibility but the powder lacks in rich oil taste and has an undesirable taste, thus is not satisfactory.
In Japanese Patent Laid-Open No. 6-271892, disclosed is a technique of solidifying a glyceride oil/fat containing, as a constitutive fatty acid, highly unsaturated fatty acids by mixing it with Zein. But, hydrolysis of the glyceride cannot be suppressed, leading to insufficient taste and storage stability.
In addition, a cooking oil/fat containing partial glycerides having a sum of a saponification value and a hydroxyl value falling within a predetermined range, and a powder thereof are disclosed (Japanese Patent Application Laid-Open No. 2000-217513). The oil/fat however has problems in taste such as shortage of oil taste and storage stability and at the same time, cakes are formed during preparation.
It is known from the previous researches that diglycerides have effects for suppressing body fat accumulation (Japanese Patent Laid-Open No. 4-300826, Japanese Patent Laid-Open No. 10-176181). It is very important to powder an oil/fat containing diglycerides having a unique health-promoting function, more specifically, capable of suppressing body fat accumulation in order to expand its application range.
Only application of the conventional powdering technique to a diglycerides-rich oil/fat however sometimes causes such problems as that the oil/fat thus powdered is insufficient in taste, texture and storage stability, and that a large amount of cakes appear during preparation.
An object of the present invention is therefore to provide an oil/fat powder containing diglycerides, being excellent in taste, texture, storage stability and dispersibility in water, and at the same time, having good dispersibility in powders such as protein and carbohydrate; and a processed food containing the oil/fat powder.